1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Userspace block device - block device which IO is handled from userspace
5 * Take full use of io_uring passthrough command for communicating with
6 * ublk userspace daemon(ublksrvd) for handling basic IO request.
8 * Copyright 2022 Ming Lei <ming.lei@redhat.com>
10 * (part of code stolen from loop.c)
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/sched.h>
16 #include <linux/pagemap.h>
17 #include <linux/file.h>
18 #include <linux/stat.h>
19 #include <linux/errno.h>
20 #include <linux/major.h>
21 #include <linux/wait.h>
22 #include <linux/blkdev.h>
23 #include <linux/init.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/compat.h>
27 #include <linux/mutex.h>
28 #include <linux/writeback.h>
29 #include <linux/completion.h>
30 #include <linux/highmem.h>
31 #include <linux/sysfs.h>
32 #include <linux/miscdevice.h>
33 #include <linux/falloc.h>
34 #include <linux/uio.h>
35 #include <linux/ioprio.h>
36 #include <linux/sched/mm.h>
37 #include <linux/uaccess.h>
38 #include <linux/cdev.h>
39 #include <linux/io_uring.h>
40 #include <linux/blk-mq.h>
41 #include <linux/delay.h>
44 #include <linux/task_work.h>
45 #include <linux/namei.h>
46 #include <uapi/linux/ublk_cmd.h>
48 #define UBLK_MINORS (1U << MINORBITS)
50 /* All UBLK_F_* have to be included into UBLK_F_ALL */
51 #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \
52 | UBLK_F_URING_CMD_COMP_IN_TASK \
53 | UBLK_F_NEED_GET_DATA \
54 | UBLK_F_USER_RECOVERY \
55 | UBLK_F_USER_RECOVERY_REISSUE \
56 | UBLK_F_UNPRIVILEGED_DEV)
58 /* All UBLK_PARAM_TYPE_* should be included here */
59 #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \
60 UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT)
63 struct llist_node node
;
64 struct callback_head work
;
67 struct ublk_uring_cmd_pdu
{
68 struct ublk_queue
*ubq
;
72 * io command is active: sqe cmd is received, and its cqe isn't done
74 * If the flag is set, the io command is owned by ublk driver, and waited
75 * for incoming blk-mq request from the ublk block device.
77 * If the flag is cleared, the io command will be completed, and owned by
80 #define UBLK_IO_FLAG_ACTIVE 0x01
83 * IO command is completed via cqe, and it is being handled by ublksrv, and
86 * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for
89 #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
92 * IO command is aborted, so this flag is set in case of
93 * !UBLK_IO_FLAG_ACTIVE.
95 * After this flag is observed, any pending or new incoming request
96 * associated with this io command will be failed immediately
98 #define UBLK_IO_FLAG_ABORTED 0x04
101 * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
102 * get data buffer address from ublksrv.
104 * Then, bio data could be copied into this data buffer for a WRITE request
105 * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
107 #define UBLK_IO_FLAG_NEED_GET_DATA 0x08
110 /* userspace buffer address from io cmd */
115 struct io_uring_cmd
*cmd
;
123 struct task_struct
*ubq_daemon
;
126 struct llist_head io_cmds
;
128 unsigned long io_addr
; /* mapped vm address */
129 unsigned int max_io_sz
;
131 unsigned short nr_io_ready
; /* how many ios setup */
132 struct ublk_device
*dev
;
133 struct ublk_io ios
[];
136 #define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ)
139 struct gendisk
*ub_disk
;
143 unsigned int queue_size
;
144 struct ublksrv_ctrl_dev_info dev_info
;
146 struct blk_mq_tag_set tag_set
;
149 struct device cdev_dev
;
151 #define UB_STATE_OPEN 0
152 #define UB_STATE_USED 1
153 #define UB_STATE_DELETED 2
160 struct mm_struct
*mm
;
162 struct ublk_params params
;
164 struct completion completion
;
165 unsigned int nr_queues_ready
;
166 unsigned int nr_privileged_daemon
;
169 * Our ubq->daemon may be killed without any notification, so
170 * monitor each queue's daemon periodically
172 struct delayed_work monitor_work
;
173 struct work_struct quiesce_work
;
174 struct work_struct stop_work
;
177 /* header of ublk_params */
178 struct ublk_params_header
{
183 static dev_t ublk_chr_devt
;
184 static struct class *ublk_chr_class
;
186 static DEFINE_IDR(ublk_index_idr
);
187 static DEFINE_SPINLOCK(ublk_idr_lock
);
188 static wait_queue_head_t ublk_idr_wq
; /* wait until one idr is freed */
190 static DEFINE_MUTEX(ublk_ctl_mutex
);
193 * Max ublk devices allowed to add
195 * It can be extended to one per-user limit in future or even controlled
198 static unsigned int ublks_max
= 64;
199 static unsigned int ublks_added
; /* protected by ublk_ctl_mutex */
201 static struct miscdevice ublk_misc
;
203 static void ublk_dev_param_basic_apply(struct ublk_device
*ub
)
205 struct request_queue
*q
= ub
->ub_disk
->queue
;
206 const struct ublk_param_basic
*p
= &ub
->params
.basic
;
208 blk_queue_logical_block_size(q
, 1 << p
->logical_bs_shift
);
209 blk_queue_physical_block_size(q
, 1 << p
->physical_bs_shift
);
210 blk_queue_io_min(q
, 1 << p
->io_min_shift
);
211 blk_queue_io_opt(q
, 1 << p
->io_opt_shift
);
213 blk_queue_write_cache(q
, p
->attrs
& UBLK_ATTR_VOLATILE_CACHE
,
214 p
->attrs
& UBLK_ATTR_FUA
);
215 if (p
->attrs
& UBLK_ATTR_ROTATIONAL
)
216 blk_queue_flag_clear(QUEUE_FLAG_NONROT
, q
);
218 blk_queue_flag_set(QUEUE_FLAG_NONROT
, q
);
220 blk_queue_max_hw_sectors(q
, p
->max_sectors
);
221 blk_queue_chunk_sectors(q
, p
->chunk_sectors
);
222 blk_queue_virt_boundary(q
, p
->virt_boundary_mask
);
224 if (p
->attrs
& UBLK_ATTR_READ_ONLY
)
225 set_disk_ro(ub
->ub_disk
, true);
227 set_capacity(ub
->ub_disk
, p
->dev_sectors
);
230 static void ublk_dev_param_discard_apply(struct ublk_device
*ub
)
232 struct request_queue
*q
= ub
->ub_disk
->queue
;
233 const struct ublk_param_discard
*p
= &ub
->params
.discard
;
235 q
->limits
.discard_alignment
= p
->discard_alignment
;
236 q
->limits
.discard_granularity
= p
->discard_granularity
;
237 blk_queue_max_discard_sectors(q
, p
->max_discard_sectors
);
238 blk_queue_max_write_zeroes_sectors(q
,
239 p
->max_write_zeroes_sectors
);
240 blk_queue_max_discard_segments(q
, p
->max_discard_segments
);
243 static int ublk_validate_params(const struct ublk_device
*ub
)
245 /* basic param is the only one which must be set */
246 if (ub
->params
.types
& UBLK_PARAM_TYPE_BASIC
) {
247 const struct ublk_param_basic
*p
= &ub
->params
.basic
;
249 if (p
->logical_bs_shift
> PAGE_SHIFT
)
252 if (p
->logical_bs_shift
> p
->physical_bs_shift
)
255 if (p
->max_sectors
> (ub
->dev_info
.max_io_buf_bytes
>> 9))
260 if (ub
->params
.types
& UBLK_PARAM_TYPE_DISCARD
) {
261 const struct ublk_param_discard
*p
= &ub
->params
.discard
;
263 /* So far, only support single segment discard */
264 if (p
->max_discard_sectors
&& p
->max_discard_segments
!= 1)
267 if (!p
->discard_granularity
)
271 /* dev_t is read-only */
272 if (ub
->params
.types
& UBLK_PARAM_TYPE_DEVT
)
278 static int ublk_apply_params(struct ublk_device
*ub
)
280 if (!(ub
->params
.types
& UBLK_PARAM_TYPE_BASIC
))
283 ublk_dev_param_basic_apply(ub
);
285 if (ub
->params
.types
& UBLK_PARAM_TYPE_DISCARD
)
286 ublk_dev_param_discard_apply(ub
);
291 static inline bool ublk_can_use_task_work(const struct ublk_queue
*ubq
)
293 if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK
) &&
294 !(ubq
->flags
& UBLK_F_URING_CMD_COMP_IN_TASK
))
299 static inline bool ublk_need_get_data(const struct ublk_queue
*ubq
)
301 if (ubq
->flags
& UBLK_F_NEED_GET_DATA
)
306 static struct ublk_device
*ublk_get_device(struct ublk_device
*ub
)
308 if (kobject_get_unless_zero(&ub
->cdev_dev
.kobj
))
313 static void ublk_put_device(struct ublk_device
*ub
)
315 put_device(&ub
->cdev_dev
);
318 static inline struct ublk_queue
*ublk_get_queue(struct ublk_device
*dev
,
321 return (struct ublk_queue
*)&(dev
->__queues
[qid
* dev
->queue_size
]);
324 static inline bool ublk_rq_has_data(const struct request
*rq
)
326 return bio_has_data(rq
->bio
);
329 static inline struct ublksrv_io_desc
*ublk_get_iod(struct ublk_queue
*ubq
,
332 return (struct ublksrv_io_desc
*)
333 &(ubq
->io_cmd_buf
[tag
* sizeof(struct ublksrv_io_desc
)]);
336 static inline char *ublk_queue_cmd_buf(struct ublk_device
*ub
, int q_id
)
338 return ublk_get_queue(ub
, q_id
)->io_cmd_buf
;
341 static inline int ublk_queue_cmd_buf_size(struct ublk_device
*ub
, int q_id
)
343 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
345 return round_up(ubq
->q_depth
* sizeof(struct ublksrv_io_desc
),
349 static inline bool ublk_queue_can_use_recovery_reissue(
350 struct ublk_queue
*ubq
)
352 if ((ubq
->flags
& UBLK_F_USER_RECOVERY
) &&
353 (ubq
->flags
& UBLK_F_USER_RECOVERY_REISSUE
))
358 static inline bool ublk_queue_can_use_recovery(
359 struct ublk_queue
*ubq
)
361 if (ubq
->flags
& UBLK_F_USER_RECOVERY
)
366 static inline bool ublk_can_use_recovery(struct ublk_device
*ub
)
368 if (ub
->dev_info
.flags
& UBLK_F_USER_RECOVERY
)
373 static void ublk_free_disk(struct gendisk
*disk
)
375 struct ublk_device
*ub
= disk
->private_data
;
377 clear_bit(UB_STATE_USED
, &ub
->state
);
378 put_device(&ub
->cdev_dev
);
381 static void ublk_store_owner_uid_gid(unsigned int *owner_uid
,
382 unsigned int *owner_gid
)
387 current_uid_gid(&uid
, &gid
);
389 *owner_uid
= from_kuid(&init_user_ns
, uid
);
390 *owner_gid
= from_kgid(&init_user_ns
, gid
);
393 static int ublk_open(struct block_device
*bdev
, fmode_t mode
)
395 struct ublk_device
*ub
= bdev
->bd_disk
->private_data
;
397 if (capable(CAP_SYS_ADMIN
))
401 * If it is one unprivileged device, only owner can open
402 * the disk. Otherwise it could be one trap made by one
403 * evil user who grants this disk's privileges to other
404 * users deliberately.
406 * This way is reasonable too given anyone can create
407 * unprivileged device, and no need other's grant.
409 if (ub
->dev_info
.flags
& UBLK_F_UNPRIVILEGED_DEV
) {
410 unsigned int curr_uid
, curr_gid
;
412 ublk_store_owner_uid_gid(&curr_uid
, &curr_gid
);
414 if (curr_uid
!= ub
->dev_info
.owner_uid
|| curr_gid
!=
415 ub
->dev_info
.owner_gid
)
422 static const struct block_device_operations ub_fops
= {
423 .owner
= THIS_MODULE
,
425 .free_disk
= ublk_free_disk
,
428 #define UBLK_MAX_PIN_PAGES 32
430 struct ublk_map_data
{
431 const struct ublk_queue
*ubq
;
432 const struct request
*rq
;
433 const struct ublk_io
*io
;
437 struct ublk_io_iter
{
438 struct page
*pages
[UBLK_MAX_PIN_PAGES
];
439 unsigned pg_off
; /* offset in the 1st page in pages */
440 int nr_pages
; /* how many page pointers in pages */
442 struct bvec_iter iter
;
445 static inline unsigned ublk_copy_io_pages(struct ublk_io_iter
*data
,
446 unsigned max_bytes
, bool to_vm
)
448 const unsigned total
= min_t(unsigned, max_bytes
,
449 PAGE_SIZE
- data
->pg_off
+
450 ((data
->nr_pages
- 1) << PAGE_SHIFT
));
454 while (done
< total
) {
455 struct bio_vec bv
= bio_iter_iovec(data
->bio
, data
->iter
);
456 const unsigned int bytes
= min3(bv
.bv_len
, total
- done
,
457 (unsigned)(PAGE_SIZE
- data
->pg_off
));
458 void *bv_buf
= bvec_kmap_local(&bv
);
459 void *pg_buf
= kmap_local_page(data
->pages
[pg_idx
]);
462 memcpy(pg_buf
+ data
->pg_off
, bv_buf
, bytes
);
464 memcpy(bv_buf
, pg_buf
+ data
->pg_off
, bytes
);
466 kunmap_local(pg_buf
);
467 kunmap_local(bv_buf
);
469 /* advance page array */
470 data
->pg_off
+= bytes
;
471 if (data
->pg_off
== PAGE_SIZE
) {
479 bio_advance_iter_single(data
->bio
, &data
->iter
, bytes
);
480 if (!data
->iter
.bi_size
) {
481 data
->bio
= data
->bio
->bi_next
;
482 if (data
->bio
== NULL
)
484 data
->iter
= data
->bio
->bi_iter
;
491 static inline int ublk_copy_user_pages(struct ublk_map_data
*data
,
494 const unsigned int gup_flags
= to_vm
? FOLL_WRITE
: 0;
495 const unsigned long start_vm
= data
->io
->addr
;
496 unsigned int done
= 0;
497 struct ublk_io_iter iter
= {
498 .pg_off
= start_vm
& (PAGE_SIZE
- 1),
499 .bio
= data
->rq
->bio
,
500 .iter
= data
->rq
->bio
->bi_iter
,
502 const unsigned int nr_pages
= round_up(data
->max_bytes
+
503 (start_vm
& (PAGE_SIZE
- 1)), PAGE_SIZE
) >> PAGE_SHIFT
;
505 while (done
< nr_pages
) {
506 const unsigned to_pin
= min_t(unsigned, UBLK_MAX_PIN_PAGES
,
510 iter
.nr_pages
= get_user_pages_fast(start_vm
+
511 (done
<< PAGE_SHIFT
), to_pin
, gup_flags
,
513 if (iter
.nr_pages
<= 0)
514 return done
== 0 ? iter
.nr_pages
: done
;
515 len
= ublk_copy_io_pages(&iter
, data
->max_bytes
, to_vm
);
516 for (i
= 0; i
< iter
.nr_pages
; i
++) {
518 set_page_dirty(iter
.pages
[i
]);
519 put_page(iter
.pages
[i
]);
521 data
->max_bytes
-= len
;
522 done
+= iter
.nr_pages
;
528 static int ublk_map_io(const struct ublk_queue
*ubq
, const struct request
*req
,
531 const unsigned int rq_bytes
= blk_rq_bytes(req
);
534 * no zero copy, we delay copy WRITE request data into ublksrv
535 * context and the big benefit is that pinning pages in current
536 * context is pretty fast, see ublk_pin_user_pages
538 if (ublk_rq_has_data(req
) && req_op(req
) == REQ_OP_WRITE
) {
539 struct ublk_map_data data
= {
543 .max_bytes
= rq_bytes
,
546 ublk_copy_user_pages(&data
, true);
548 return rq_bytes
- data
.max_bytes
;
553 static int ublk_unmap_io(const struct ublk_queue
*ubq
,
554 const struct request
*req
,
557 const unsigned int rq_bytes
= blk_rq_bytes(req
);
559 if (req_op(req
) == REQ_OP_READ
&& ublk_rq_has_data(req
)) {
560 struct ublk_map_data data
= {
564 .max_bytes
= io
->res
,
567 WARN_ON_ONCE(io
->res
> rq_bytes
);
569 ublk_copy_user_pages(&data
, false);
571 return io
->res
- data
.max_bytes
;
576 static inline unsigned int ublk_req_build_flags(struct request
*req
)
580 if (req
->cmd_flags
& REQ_FAILFAST_DEV
)
581 flags
|= UBLK_IO_F_FAILFAST_DEV
;
583 if (req
->cmd_flags
& REQ_FAILFAST_TRANSPORT
)
584 flags
|= UBLK_IO_F_FAILFAST_TRANSPORT
;
586 if (req
->cmd_flags
& REQ_FAILFAST_DRIVER
)
587 flags
|= UBLK_IO_F_FAILFAST_DRIVER
;
589 if (req
->cmd_flags
& REQ_META
)
590 flags
|= UBLK_IO_F_META
;
592 if (req
->cmd_flags
& REQ_FUA
)
593 flags
|= UBLK_IO_F_FUA
;
595 if (req
->cmd_flags
& REQ_NOUNMAP
)
596 flags
|= UBLK_IO_F_NOUNMAP
;
598 if (req
->cmd_flags
& REQ_SWAP
)
599 flags
|= UBLK_IO_F_SWAP
;
604 static blk_status_t
ublk_setup_iod(struct ublk_queue
*ubq
, struct request
*req
)
606 struct ublksrv_io_desc
*iod
= ublk_get_iod(ubq
, req
->tag
);
607 struct ublk_io
*io
= &ubq
->ios
[req
->tag
];
610 switch (req_op(req
)) {
612 ublk_op
= UBLK_IO_OP_READ
;
615 ublk_op
= UBLK_IO_OP_WRITE
;
618 ublk_op
= UBLK_IO_OP_FLUSH
;
621 ublk_op
= UBLK_IO_OP_DISCARD
;
623 case REQ_OP_WRITE_ZEROES
:
624 ublk_op
= UBLK_IO_OP_WRITE_ZEROES
;
627 return BLK_STS_IOERR
;
630 /* need to translate since kernel may change */
631 iod
->op_flags
= ublk_op
| ublk_req_build_flags(req
);
632 iod
->nr_sectors
= blk_rq_sectors(req
);
633 iod
->start_sector
= blk_rq_pos(req
);
634 iod
->addr
= io
->addr
;
639 static inline struct ublk_uring_cmd_pdu
*ublk_get_uring_cmd_pdu(
640 struct io_uring_cmd
*ioucmd
)
642 return (struct ublk_uring_cmd_pdu
*)&ioucmd
->pdu
;
645 static inline bool ubq_daemon_is_dying(struct ublk_queue
*ubq
)
647 return ubq
->ubq_daemon
->flags
& PF_EXITING
;
650 /* todo: handle partial completion */
651 static void ublk_complete_rq(struct request
*req
)
653 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
654 struct ublk_io
*io
= &ubq
->ios
[req
->tag
];
655 unsigned int unmapped_bytes
;
656 blk_status_t res
= BLK_STS_OK
;
658 /* failed read IO if nothing is read */
659 if (!io
->res
&& req_op(req
) == REQ_OP_READ
)
663 res
= errno_to_blk_status(io
->res
);
668 * FLUSH, DISCARD or WRITE_ZEROES usually won't return bytes returned, so end them
671 * Both the two needn't unmap.
673 if (req_op(req
) != REQ_OP_READ
&& req_op(req
) != REQ_OP_WRITE
)
676 /* for READ request, writing data in iod->addr to rq buffers */
677 unmapped_bytes
= ublk_unmap_io(ubq
, req
, io
);
680 * Extremely impossible since we got data filled in just before
682 * Re-read simply for this unlikely case.
684 if (unlikely(unmapped_bytes
< io
->res
))
685 io
->res
= unmapped_bytes
;
687 if (blk_update_request(req
, BLK_STS_OK
, io
->res
))
688 blk_mq_requeue_request(req
, true);
690 __blk_mq_end_request(req
, BLK_STS_OK
);
694 blk_mq_end_request(req
, res
);
698 * Since __ublk_rq_task_work always fails requests immediately during
699 * exiting, __ublk_fail_req() is only called from abort context during
700 * exiting. So lock is unnecessary.
702 * Also aborting may not be started yet, keep in mind that one failed
703 * request may be issued by block layer again.
705 static void __ublk_fail_req(struct ublk_queue
*ubq
, struct ublk_io
*io
,
708 WARN_ON_ONCE(io
->flags
& UBLK_IO_FLAG_ACTIVE
);
710 if (!(io
->flags
& UBLK_IO_FLAG_ABORTED
)) {
711 io
->flags
|= UBLK_IO_FLAG_ABORTED
;
712 if (ublk_queue_can_use_recovery_reissue(ubq
))
713 blk_mq_requeue_request(req
, false);
715 blk_mq_end_request(req
, BLK_STS_IOERR
);
719 static void ubq_complete_io_cmd(struct ublk_io
*io
, int res
)
721 /* mark this cmd owned by ublksrv */
722 io
->flags
|= UBLK_IO_FLAG_OWNED_BY_SRV
;
725 * clear ACTIVE since we are done with this sqe/cmd slot
726 * We can only accept io cmd in case of being not active.
728 io
->flags
&= ~UBLK_IO_FLAG_ACTIVE
;
730 /* tell ublksrv one io request is coming */
731 io_uring_cmd_done(io
->cmd
, res
, 0);
734 #define UBLK_REQUEUE_DELAY_MS 3
736 static inline void __ublk_abort_rq(struct ublk_queue
*ubq
,
739 /* We cannot process this rq so just requeue it. */
740 if (ublk_queue_can_use_recovery(ubq
))
741 blk_mq_requeue_request(rq
, false);
743 blk_mq_end_request(rq
, BLK_STS_IOERR
);
745 mod_delayed_work(system_wq
, &ubq
->dev
->monitor_work
, 0);
748 static inline void __ublk_rq_task_work(struct request
*req
)
750 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
752 struct ublk_io
*io
= &ubq
->ios
[tag
];
753 unsigned int mapped_bytes
;
755 pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n",
756 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
, req
->tag
, io
->flags
,
757 ublk_get_iod(ubq
, req
->tag
)->addr
);
760 * Task is exiting if either:
762 * (1) current != ubq_daemon.
763 * io_uring_cmd_complete_in_task() tries to run task_work
764 * in a workqueue if ubq_daemon(cmd's task) is PF_EXITING.
766 * (2) current->flags & PF_EXITING.
768 if (unlikely(current
!= ubq
->ubq_daemon
|| current
->flags
& PF_EXITING
)) {
769 __ublk_abort_rq(ubq
, req
);
773 if (ublk_need_get_data(ubq
) && (req_op(req
) == REQ_OP_WRITE
)) {
775 * We have not handled UBLK_IO_NEED_GET_DATA command yet,
776 * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv
779 if (!(io
->flags
& UBLK_IO_FLAG_NEED_GET_DATA
)) {
780 io
->flags
|= UBLK_IO_FLAG_NEED_GET_DATA
;
781 pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n",
782 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
,
783 req
->tag
, io
->flags
);
784 ubq_complete_io_cmd(io
, UBLK_IO_RES_NEED_GET_DATA
);
788 * We have handled UBLK_IO_NEED_GET_DATA command,
789 * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just
792 io
->flags
&= ~UBLK_IO_FLAG_NEED_GET_DATA
;
793 /* update iod->addr because ublksrv may have passed a new io buffer */
794 ublk_get_iod(ubq
, req
->tag
)->addr
= io
->addr
;
795 pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n",
796 __func__
, io
->cmd
->cmd_op
, ubq
->q_id
, req
->tag
, io
->flags
,
797 ublk_get_iod(ubq
, req
->tag
)->addr
);
800 mapped_bytes
= ublk_map_io(ubq
, req
, io
);
802 /* partially mapped, update io descriptor */
803 if (unlikely(mapped_bytes
!= blk_rq_bytes(req
))) {
805 * Nothing mapped, retry until we succeed.
807 * We may never succeed in mapping any bytes here because
808 * of OOM. TODO: reserve one buffer with single page pinned
809 * for providing forward progress guarantee.
811 if (unlikely(!mapped_bytes
)) {
812 blk_mq_requeue_request(req
, false);
813 blk_mq_delay_kick_requeue_list(req
->q
,
814 UBLK_REQUEUE_DELAY_MS
);
818 ublk_get_iod(ubq
, req
->tag
)->nr_sectors
=
822 ubq_complete_io_cmd(io
, UBLK_IO_RES_OK
);
825 static inline void ublk_forward_io_cmds(struct ublk_queue
*ubq
)
827 struct llist_node
*io_cmds
= llist_del_all(&ubq
->io_cmds
);
828 struct ublk_rq_data
*data
, *tmp
;
830 io_cmds
= llist_reverse_order(io_cmds
);
831 llist_for_each_entry_safe(data
, tmp
, io_cmds
, node
)
832 __ublk_rq_task_work(blk_mq_rq_from_pdu(data
));
835 static inline void ublk_abort_io_cmds(struct ublk_queue
*ubq
)
837 struct llist_node
*io_cmds
= llist_del_all(&ubq
->io_cmds
);
838 struct ublk_rq_data
*data
, *tmp
;
840 llist_for_each_entry_safe(data
, tmp
, io_cmds
, node
)
841 __ublk_abort_rq(ubq
, blk_mq_rq_from_pdu(data
));
844 static void ublk_rq_task_work_cb(struct io_uring_cmd
*cmd
)
846 struct ublk_uring_cmd_pdu
*pdu
= ublk_get_uring_cmd_pdu(cmd
);
847 struct ublk_queue
*ubq
= pdu
->ubq
;
849 ublk_forward_io_cmds(ubq
);
852 static void ublk_rq_task_work_fn(struct callback_head
*work
)
854 struct ublk_rq_data
*data
= container_of(work
,
855 struct ublk_rq_data
, work
);
856 struct request
*req
= blk_mq_rq_from_pdu(data
);
857 struct ublk_queue
*ubq
= req
->mq_hctx
->driver_data
;
859 ublk_forward_io_cmds(ubq
);
862 static void ublk_queue_cmd(struct ublk_queue
*ubq
, struct request
*rq
)
864 struct ublk_rq_data
*data
= blk_mq_rq_to_pdu(rq
);
867 if (!llist_add(&data
->node
, &ubq
->io_cmds
))
870 io
= &ubq
->ios
[rq
->tag
];
872 * If the check pass, we know that this is a re-issued request aborted
873 * previously in monitor_work because the ubq_daemon(cmd's task) is
874 * PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore
875 * because this ioucmd's io_uring context may be freed now if no inflight
876 * ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work.
878 * Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request(releasing
879 * the tag). Then the request is re-started(allocating the tag) and we are here.
880 * Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED
881 * guarantees that here is a re-issued request aborted previously.
883 if (unlikely(io
->flags
& UBLK_IO_FLAG_ABORTED
)) {
884 ublk_abort_io_cmds(ubq
);
885 } else if (ublk_can_use_task_work(ubq
)) {
886 if (task_work_add(ubq
->ubq_daemon
, &data
->work
,
888 ublk_abort_io_cmds(ubq
);
890 struct io_uring_cmd
*cmd
= io
->cmd
;
891 struct ublk_uring_cmd_pdu
*pdu
= ublk_get_uring_cmd_pdu(cmd
);
894 io_uring_cmd_complete_in_task(cmd
, ublk_rq_task_work_cb
);
898 static blk_status_t
ublk_queue_rq(struct blk_mq_hw_ctx
*hctx
,
899 const struct blk_mq_queue_data
*bd
)
901 struct ublk_queue
*ubq
= hctx
->driver_data
;
902 struct request
*rq
= bd
->rq
;
905 /* fill iod to slot in io cmd buffer */
906 res
= ublk_setup_iod(ubq
, rq
);
907 if (unlikely(res
!= BLK_STS_OK
))
908 return BLK_STS_IOERR
;
910 /* With recovery feature enabled, force_abort is set in
911 * ublk_stop_dev() before calling del_gendisk(). We have to
912 * abort all requeued and new rqs here to let del_gendisk()
913 * move on. Besides, we cannot not call io_uring_cmd_complete_in_task()
914 * to avoid UAF on io_uring ctx.
916 * Note: force_abort is guaranteed to be seen because it is set
917 * before request queue is unqiuesced.
919 if (ublk_queue_can_use_recovery(ubq
) && unlikely(ubq
->force_abort
))
920 return BLK_STS_IOERR
;
922 blk_mq_start_request(bd
->rq
);
924 if (unlikely(ubq_daemon_is_dying(ubq
))) {
925 __ublk_abort_rq(ubq
, rq
);
929 ublk_queue_cmd(ubq
, rq
);
934 static int ublk_init_hctx(struct blk_mq_hw_ctx
*hctx
, void *driver_data
,
935 unsigned int hctx_idx
)
937 struct ublk_device
*ub
= driver_data
;
938 struct ublk_queue
*ubq
= ublk_get_queue(ub
, hctx
->queue_num
);
940 hctx
->driver_data
= ubq
;
944 static int ublk_init_rq(struct blk_mq_tag_set
*set
, struct request
*req
,
945 unsigned int hctx_idx
, unsigned int numa_node
)
947 struct ublk_rq_data
*data
= blk_mq_rq_to_pdu(req
);
949 init_task_work(&data
->work
, ublk_rq_task_work_fn
);
953 static const struct blk_mq_ops ublk_mq_ops
= {
954 .queue_rq
= ublk_queue_rq
,
955 .init_hctx
= ublk_init_hctx
,
956 .init_request
= ublk_init_rq
,
959 static int ublk_ch_open(struct inode
*inode
, struct file
*filp
)
961 struct ublk_device
*ub
= container_of(inode
->i_cdev
,
962 struct ublk_device
, cdev
);
964 if (test_and_set_bit(UB_STATE_OPEN
, &ub
->state
))
966 filp
->private_data
= ub
;
970 static int ublk_ch_release(struct inode
*inode
, struct file
*filp
)
972 struct ublk_device
*ub
= filp
->private_data
;
974 clear_bit(UB_STATE_OPEN
, &ub
->state
);
978 /* map pre-allocated per-queue cmd buffer to ublksrv daemon */
979 static int ublk_ch_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
981 struct ublk_device
*ub
= filp
->private_data
;
982 size_t sz
= vma
->vm_end
- vma
->vm_start
;
983 unsigned max_sz
= UBLK_MAX_QUEUE_DEPTH
* sizeof(struct ublksrv_io_desc
);
984 unsigned long pfn
, end
, phys_off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
987 spin_lock(&ub
->mm_lock
);
989 ub
->mm
= current
->mm
;
990 if (current
->mm
!= ub
->mm
)
992 spin_unlock(&ub
->mm_lock
);
997 if (vma
->vm_flags
& VM_WRITE
)
1000 end
= UBLKSRV_CMD_BUF_OFFSET
+ ub
->dev_info
.nr_hw_queues
* max_sz
;
1001 if (phys_off
< UBLKSRV_CMD_BUF_OFFSET
|| phys_off
>= end
)
1004 q_id
= (phys_off
- UBLKSRV_CMD_BUF_OFFSET
) / max_sz
;
1005 pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n",
1006 __func__
, q_id
, current
->pid
, vma
->vm_start
,
1007 phys_off
, (unsigned long)sz
);
1009 if (sz
!= ublk_queue_cmd_buf_size(ub
, q_id
))
1012 pfn
= virt_to_phys(ublk_queue_cmd_buf(ub
, q_id
)) >> PAGE_SHIFT
;
1013 return remap_pfn_range(vma
, vma
->vm_start
, pfn
, sz
, vma
->vm_page_prot
);
1016 static void ublk_commit_completion(struct ublk_device
*ub
,
1017 struct ublksrv_io_cmd
*ub_cmd
)
1019 u32 qid
= ub_cmd
->q_id
, tag
= ub_cmd
->tag
;
1020 struct ublk_queue
*ubq
= ublk_get_queue(ub
, qid
);
1021 struct ublk_io
*io
= &ubq
->ios
[tag
];
1022 struct request
*req
;
1024 /* now this cmd slot is owned by nbd driver */
1025 io
->flags
&= ~UBLK_IO_FLAG_OWNED_BY_SRV
;
1026 io
->res
= ub_cmd
->result
;
1028 /* find the io request and complete */
1029 req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[qid
], tag
);
1031 if (req
&& likely(!blk_should_fake_timeout(req
->q
)))
1032 ublk_complete_rq(req
);
1036 * When ->ubq_daemon is exiting, either new request is ended immediately,
1037 * or any queued io command is drained, so it is safe to abort queue
1040 static void ublk_abort_queue(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1044 if (!ublk_get_device(ub
))
1047 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1048 struct ublk_io
*io
= &ubq
->ios
[i
];
1050 if (!(io
->flags
& UBLK_IO_FLAG_ACTIVE
)) {
1054 * Either we fail the request or ublk_rq_task_work_fn
1057 rq
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[ubq
->q_id
], i
);
1059 __ublk_fail_req(ubq
, io
, rq
);
1062 ublk_put_device(ub
);
1065 static void ublk_daemon_monitor_work(struct work_struct
*work
)
1067 struct ublk_device
*ub
=
1068 container_of(work
, struct ublk_device
, monitor_work
.work
);
1071 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++) {
1072 struct ublk_queue
*ubq
= ublk_get_queue(ub
, i
);
1074 if (ubq_daemon_is_dying(ubq
)) {
1075 if (ublk_queue_can_use_recovery(ubq
))
1076 schedule_work(&ub
->quiesce_work
);
1078 schedule_work(&ub
->stop_work
);
1080 /* abort queue is for making forward progress */
1081 ublk_abort_queue(ub
, ubq
);
1086 * We can't schedule monitor work after ub's state is not UBLK_S_DEV_LIVE.
1087 * after ublk_remove() or __ublk_quiesce_dev() is started.
1089 * No need ub->mutex, monitor work are canceled after state is marked
1090 * as not LIVE, so new state is observed reliably.
1092 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
)
1093 schedule_delayed_work(&ub
->monitor_work
,
1094 UBLK_DAEMON_MONITOR_PERIOD
);
1097 static inline bool ublk_queue_ready(struct ublk_queue
*ubq
)
1099 return ubq
->nr_io_ready
== ubq
->q_depth
;
1102 static void ublk_cancel_queue(struct ublk_queue
*ubq
)
1106 if (!ublk_queue_ready(ubq
))
1109 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1110 struct ublk_io
*io
= &ubq
->ios
[i
];
1112 if (io
->flags
& UBLK_IO_FLAG_ACTIVE
)
1113 io_uring_cmd_done(io
->cmd
, UBLK_IO_RES_ABORT
, 0);
1116 /* all io commands are canceled */
1117 ubq
->nr_io_ready
= 0;
1120 /* Cancel all pending commands, must be called after del_gendisk() returns */
1121 static void ublk_cancel_dev(struct ublk_device
*ub
)
1125 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
1126 ublk_cancel_queue(ublk_get_queue(ub
, i
));
1129 static bool ublk_check_inflight_rq(struct request
*rq
, void *data
)
1133 if (blk_mq_request_started(rq
)) {
1140 static void ublk_wait_tagset_rqs_idle(struct ublk_device
*ub
)
1144 WARN_ON_ONCE(!blk_queue_quiesced(ub
->ub_disk
->queue
));
1147 blk_mq_tagset_busy_iter(&ub
->tag_set
,
1148 ublk_check_inflight_rq
, &idle
);
1151 msleep(UBLK_REQUEUE_DELAY_MS
);
1155 static void __ublk_quiesce_dev(struct ublk_device
*ub
)
1157 pr_devel("%s: quiesce ub: dev_id %d state %s\n",
1158 __func__
, ub
->dev_info
.dev_id
,
1159 ub
->dev_info
.state
== UBLK_S_DEV_LIVE
?
1160 "LIVE" : "QUIESCED");
1161 blk_mq_quiesce_queue(ub
->ub_disk
->queue
);
1162 ublk_wait_tagset_rqs_idle(ub
);
1163 ub
->dev_info
.state
= UBLK_S_DEV_QUIESCED
;
1164 ublk_cancel_dev(ub
);
1165 /* we are going to release task_struct of ubq_daemon and resets
1166 * ->ubq_daemon to NULL. So in monitor_work, check on ubq_daemon causes UAF.
1167 * Besides, monitor_work is not necessary in QUIESCED state since we have
1168 * already scheduled quiesce_work and quiesced all ubqs.
1170 * Do not let monitor_work schedule itself if state it QUIESCED. And we cancel
1171 * it here and re-schedule it in END_USER_RECOVERY to avoid UAF.
1173 cancel_delayed_work_sync(&ub
->monitor_work
);
1176 static void ublk_quiesce_work_fn(struct work_struct
*work
)
1178 struct ublk_device
*ub
=
1179 container_of(work
, struct ublk_device
, quiesce_work
);
1181 mutex_lock(&ub
->mutex
);
1182 if (ub
->dev_info
.state
!= UBLK_S_DEV_LIVE
)
1184 __ublk_quiesce_dev(ub
);
1186 mutex_unlock(&ub
->mutex
);
1189 static void ublk_unquiesce_dev(struct ublk_device
*ub
)
1193 pr_devel("%s: unquiesce ub: dev_id %d state %s\n",
1194 __func__
, ub
->dev_info
.dev_id
,
1195 ub
->dev_info
.state
== UBLK_S_DEV_LIVE
?
1196 "LIVE" : "QUIESCED");
1197 /* quiesce_work has run. We let requeued rqs be aborted
1198 * before running fallback_wq. "force_abort" must be seen
1199 * after request queue is unqiuesced. Then del_gendisk()
1202 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
1203 ublk_get_queue(ub
, i
)->force_abort
= true;
1205 blk_mq_unquiesce_queue(ub
->ub_disk
->queue
);
1206 /* We may have requeued some rqs in ublk_quiesce_queue() */
1207 blk_mq_kick_requeue_list(ub
->ub_disk
->queue
);
1210 static void ublk_stop_dev(struct ublk_device
*ub
)
1212 mutex_lock(&ub
->mutex
);
1213 if (ub
->dev_info
.state
== UBLK_S_DEV_DEAD
)
1215 if (ublk_can_use_recovery(ub
)) {
1216 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
)
1217 __ublk_quiesce_dev(ub
);
1218 ublk_unquiesce_dev(ub
);
1220 del_gendisk(ub
->ub_disk
);
1221 ub
->dev_info
.state
= UBLK_S_DEV_DEAD
;
1222 ub
->dev_info
.ublksrv_pid
= -1;
1223 put_disk(ub
->ub_disk
);
1226 ublk_cancel_dev(ub
);
1227 mutex_unlock(&ub
->mutex
);
1228 cancel_delayed_work_sync(&ub
->monitor_work
);
1231 /* device can only be started after all IOs are ready */
1232 static void ublk_mark_io_ready(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1234 mutex_lock(&ub
->mutex
);
1236 if (ublk_queue_ready(ubq
)) {
1237 ubq
->ubq_daemon
= current
;
1238 get_task_struct(ubq
->ubq_daemon
);
1239 ub
->nr_queues_ready
++;
1241 if (capable(CAP_SYS_ADMIN
))
1242 ub
->nr_privileged_daemon
++;
1244 if (ub
->nr_queues_ready
== ub
->dev_info
.nr_hw_queues
)
1245 complete_all(&ub
->completion
);
1246 mutex_unlock(&ub
->mutex
);
1249 static void ublk_handle_need_get_data(struct ublk_device
*ub
, int q_id
,
1252 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1253 struct request
*req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[q_id
], tag
);
1255 ublk_queue_cmd(ubq
, req
);
1258 static int ublk_ch_uring_cmd(struct io_uring_cmd
*cmd
, unsigned int issue_flags
)
1260 struct ublksrv_io_cmd
*ub_cmd
= (struct ublksrv_io_cmd
*)cmd
->cmd
;
1261 struct ublk_device
*ub
= cmd
->file
->private_data
;
1262 struct ublk_queue
*ubq
;
1264 u32 cmd_op
= cmd
->cmd_op
;
1265 unsigned tag
= ub_cmd
->tag
;
1267 struct request
*req
;
1269 pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n",
1270 __func__
, cmd
->cmd_op
, ub_cmd
->q_id
, tag
,
1273 if (ub_cmd
->q_id
>= ub
->dev_info
.nr_hw_queues
)
1276 ubq
= ublk_get_queue(ub
, ub_cmd
->q_id
);
1277 if (!ubq
|| ub_cmd
->q_id
!= ubq
->q_id
)
1280 if (ubq
->ubq_daemon
&& ubq
->ubq_daemon
!= current
)
1283 if (tag
>= ubq
->q_depth
)
1286 io
= &ubq
->ios
[tag
];
1288 /* there is pending io cmd, something must be wrong */
1289 if (io
->flags
& UBLK_IO_FLAG_ACTIVE
) {
1295 * ensure that the user issues UBLK_IO_NEED_GET_DATA
1296 * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA.
1298 if ((!!(io
->flags
& UBLK_IO_FLAG_NEED_GET_DATA
))
1299 ^ (cmd_op
== UBLK_IO_NEED_GET_DATA
))
1303 case UBLK_IO_FETCH_REQ
:
1304 /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */
1305 if (ublk_queue_ready(ubq
)) {
1310 * The io is being handled by server, so COMMIT_RQ is expected
1311 * instead of FETCH_REQ
1313 if (io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
)
1315 /* FETCH_RQ has to provide IO buffer if NEED GET DATA is not enabled */
1316 if (!ub_cmd
->addr
&& !ublk_need_get_data(ubq
))
1319 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1320 io
->addr
= ub_cmd
->addr
;
1322 ublk_mark_io_ready(ub
, ubq
);
1324 case UBLK_IO_COMMIT_AND_FETCH_REQ
:
1325 req
= blk_mq_tag_to_rq(ub
->tag_set
.tags
[ub_cmd
->q_id
], tag
);
1327 * COMMIT_AND_FETCH_REQ has to provide IO buffer if NEED GET DATA is
1328 * not enabled or it is Read IO.
1330 if (!ub_cmd
->addr
&& (!ublk_need_get_data(ubq
) || req_op(req
) == REQ_OP_READ
))
1332 if (!(io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
))
1334 io
->addr
= ub_cmd
->addr
;
1335 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1337 ublk_commit_completion(ub
, ub_cmd
);
1339 case UBLK_IO_NEED_GET_DATA
:
1340 if (!(io
->flags
& UBLK_IO_FLAG_OWNED_BY_SRV
))
1342 io
->addr
= ub_cmd
->addr
;
1344 io
->flags
|= UBLK_IO_FLAG_ACTIVE
;
1345 ublk_handle_need_get_data(ub
, ub_cmd
->q_id
, ub_cmd
->tag
);
1350 return -EIOCBQUEUED
;
1353 io_uring_cmd_done(cmd
, ret
, 0);
1354 pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n",
1355 __func__
, cmd_op
, tag
, ret
, io
->flags
);
1356 return -EIOCBQUEUED
;
1359 static const struct file_operations ublk_ch_fops
= {
1360 .owner
= THIS_MODULE
,
1361 .open
= ublk_ch_open
,
1362 .release
= ublk_ch_release
,
1363 .llseek
= no_llseek
,
1364 .uring_cmd
= ublk_ch_uring_cmd
,
1365 .mmap
= ublk_ch_mmap
,
1368 static void ublk_deinit_queue(struct ublk_device
*ub
, int q_id
)
1370 int size
= ublk_queue_cmd_buf_size(ub
, q_id
);
1371 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1373 if (ubq
->ubq_daemon
)
1374 put_task_struct(ubq
->ubq_daemon
);
1375 if (ubq
->io_cmd_buf
)
1376 free_pages((unsigned long)ubq
->io_cmd_buf
, get_order(size
));
1379 static int ublk_init_queue(struct ublk_device
*ub
, int q_id
)
1381 struct ublk_queue
*ubq
= ublk_get_queue(ub
, q_id
);
1382 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_ZERO
;
1386 ubq
->flags
= ub
->dev_info
.flags
;
1388 ubq
->q_depth
= ub
->dev_info
.queue_depth
;
1389 size
= ublk_queue_cmd_buf_size(ub
, q_id
);
1391 ptr
= (void *) __get_free_pages(gfp_flags
, get_order(size
));
1395 ubq
->io_cmd_buf
= ptr
;
1400 static void ublk_deinit_queues(struct ublk_device
*ub
)
1402 int nr_queues
= ub
->dev_info
.nr_hw_queues
;
1408 for (i
= 0; i
< nr_queues
; i
++)
1409 ublk_deinit_queue(ub
, i
);
1410 kfree(ub
->__queues
);
1413 static int ublk_init_queues(struct ublk_device
*ub
)
1415 int nr_queues
= ub
->dev_info
.nr_hw_queues
;
1416 int depth
= ub
->dev_info
.queue_depth
;
1417 int ubq_size
= sizeof(struct ublk_queue
) + depth
* sizeof(struct ublk_io
);
1418 int i
, ret
= -ENOMEM
;
1420 ub
->queue_size
= ubq_size
;
1421 ub
->__queues
= kcalloc(nr_queues
, ubq_size
, GFP_KERNEL
);
1425 for (i
= 0; i
< nr_queues
; i
++) {
1426 if (ublk_init_queue(ub
, i
))
1430 init_completion(&ub
->completion
);
1434 ublk_deinit_queues(ub
);
1438 static int ublk_alloc_dev_number(struct ublk_device
*ub
, int idx
)
1443 spin_lock(&ublk_idr_lock
);
1444 /* allocate id, if @id >= 0, we're requesting that specific id */
1446 err
= idr_alloc(&ublk_index_idr
, ub
, i
, i
+ 1, GFP_NOWAIT
);
1450 err
= idr_alloc(&ublk_index_idr
, ub
, 0, 0, GFP_NOWAIT
);
1452 spin_unlock(&ublk_idr_lock
);
1455 ub
->ub_number
= err
;
1460 static void ublk_free_dev_number(struct ublk_device
*ub
)
1462 spin_lock(&ublk_idr_lock
);
1463 idr_remove(&ublk_index_idr
, ub
->ub_number
);
1464 wake_up_all(&ublk_idr_wq
);
1465 spin_unlock(&ublk_idr_lock
);
1468 static void ublk_cdev_rel(struct device
*dev
)
1470 struct ublk_device
*ub
= container_of(dev
, struct ublk_device
, cdev_dev
);
1472 blk_mq_free_tag_set(&ub
->tag_set
);
1473 ublk_deinit_queues(ub
);
1474 ublk_free_dev_number(ub
);
1475 mutex_destroy(&ub
->mutex
);
1479 static int ublk_add_chdev(struct ublk_device
*ub
)
1481 struct device
*dev
= &ub
->cdev_dev
;
1482 int minor
= ub
->ub_number
;
1485 dev
->parent
= ublk_misc
.this_device
;
1486 dev
->devt
= MKDEV(MAJOR(ublk_chr_devt
), minor
);
1487 dev
->class = ublk_chr_class
;
1488 dev
->release
= ublk_cdev_rel
;
1489 device_initialize(dev
);
1491 ret
= dev_set_name(dev
, "ublkc%d", minor
);
1495 cdev_init(&ub
->cdev
, &ublk_ch_fops
);
1496 ret
= cdev_device_add(&ub
->cdev
, dev
);
1507 static void ublk_stop_work_fn(struct work_struct
*work
)
1509 struct ublk_device
*ub
=
1510 container_of(work
, struct ublk_device
, stop_work
);
1515 /* align max io buffer size with PAGE_SIZE */
1516 static void ublk_align_max_io_size(struct ublk_device
*ub
)
1518 unsigned int max_io_bytes
= ub
->dev_info
.max_io_buf_bytes
;
1520 ub
->dev_info
.max_io_buf_bytes
=
1521 round_down(max_io_bytes
, PAGE_SIZE
);
1524 static int ublk_add_tag_set(struct ublk_device
*ub
)
1526 ub
->tag_set
.ops
= &ublk_mq_ops
;
1527 ub
->tag_set
.nr_hw_queues
= ub
->dev_info
.nr_hw_queues
;
1528 ub
->tag_set
.queue_depth
= ub
->dev_info
.queue_depth
;
1529 ub
->tag_set
.numa_node
= NUMA_NO_NODE
;
1530 ub
->tag_set
.cmd_size
= sizeof(struct ublk_rq_data
);
1531 ub
->tag_set
.flags
= BLK_MQ_F_SHOULD_MERGE
;
1532 ub
->tag_set
.driver_data
= ub
;
1533 return blk_mq_alloc_tag_set(&ub
->tag_set
);
1536 static void ublk_remove(struct ublk_device
*ub
)
1539 cancel_work_sync(&ub
->stop_work
);
1540 cancel_work_sync(&ub
->quiesce_work
);
1541 cdev_device_del(&ub
->cdev
, &ub
->cdev_dev
);
1542 put_device(&ub
->cdev_dev
);
1546 static struct ublk_device
*ublk_get_device_from_id(int idx
)
1548 struct ublk_device
*ub
= NULL
;
1553 spin_lock(&ublk_idr_lock
);
1554 ub
= idr_find(&ublk_index_idr
, idx
);
1556 ub
= ublk_get_device(ub
);
1557 spin_unlock(&ublk_idr_lock
);
1562 static int ublk_ctrl_start_dev(struct ublk_device
*ub
, struct io_uring_cmd
*cmd
)
1564 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1565 int ublksrv_pid
= (int)header
->data
[0];
1566 struct gendisk
*disk
;
1569 if (ublksrv_pid
<= 0)
1572 wait_for_completion_interruptible(&ub
->completion
);
1574 schedule_delayed_work(&ub
->monitor_work
, UBLK_DAEMON_MONITOR_PERIOD
);
1576 mutex_lock(&ub
->mutex
);
1577 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
||
1578 test_bit(UB_STATE_USED
, &ub
->state
)) {
1583 disk
= blk_mq_alloc_disk(&ub
->tag_set
, NULL
);
1585 ret
= PTR_ERR(disk
);
1588 sprintf(disk
->disk_name
, "ublkb%d", ub
->ub_number
);
1589 disk
->fops
= &ub_fops
;
1590 disk
->private_data
= ub
;
1592 ub
->dev_info
.ublksrv_pid
= ublksrv_pid
;
1595 ret
= ublk_apply_params(ub
);
1599 /* don't probe partitions if any one ubq daemon is un-trusted */
1600 if (ub
->nr_privileged_daemon
!= ub
->nr_queues_ready
)
1601 set_bit(GD_SUPPRESS_PART_SCAN
, &disk
->state
);
1603 get_device(&ub
->cdev_dev
);
1604 ret
= add_disk(disk
);
1607 * Has to drop the reference since ->free_disk won't be
1608 * called in case of add_disk failure.
1610 ublk_put_device(ub
);
1613 set_bit(UB_STATE_USED
, &ub
->state
);
1614 ub
->dev_info
.state
= UBLK_S_DEV_LIVE
;
1619 mutex_unlock(&ub
->mutex
);
1623 static int ublk_ctrl_get_queue_affinity(struct ublk_device
*ub
,
1624 struct io_uring_cmd
*cmd
)
1626 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1627 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1628 cpumask_var_t cpumask
;
1629 unsigned long queue
;
1630 unsigned int retlen
;
1634 if (header
->len
* BITS_PER_BYTE
< nr_cpu_ids
)
1636 if (header
->len
& (sizeof(unsigned long)-1))
1641 queue
= header
->data
[0];
1642 if (queue
>= ub
->dev_info
.nr_hw_queues
)
1645 if (!zalloc_cpumask_var(&cpumask
, GFP_KERNEL
))
1648 for_each_possible_cpu(i
) {
1649 if (ub
->tag_set
.map
[HCTX_TYPE_DEFAULT
].mq_map
[i
] == queue
)
1650 cpumask_set_cpu(i
, cpumask
);
1654 retlen
= min_t(unsigned short, header
->len
, cpumask_size());
1655 if (copy_to_user(argp
, cpumask
, retlen
))
1656 goto out_free_cpumask
;
1657 if (retlen
!= header
->len
&&
1658 clear_user(argp
+ retlen
, header
->len
- retlen
))
1659 goto out_free_cpumask
;
1663 free_cpumask_var(cpumask
);
1667 static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info
*info
)
1669 pr_devel("%s: dev id %d flags %llx\n", __func__
,
1670 info
->dev_id
, info
->flags
);
1671 pr_devel("\t nr_hw_queues %d queue_depth %d\n",
1672 info
->nr_hw_queues
, info
->queue_depth
);
1675 static int ublk_ctrl_add_dev(struct io_uring_cmd
*cmd
)
1677 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1678 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1679 struct ublksrv_ctrl_dev_info info
;
1680 struct ublk_device
*ub
;
1683 if (header
->len
< sizeof(info
) || !header
->addr
)
1685 if (header
->queue_id
!= (u16
)-1) {
1686 pr_warn("%s: queue_id is wrong %x\n",
1687 __func__
, header
->queue_id
);
1691 if (copy_from_user(&info
, argp
, sizeof(info
)))
1694 if (capable(CAP_SYS_ADMIN
))
1695 info
.flags
&= ~UBLK_F_UNPRIVILEGED_DEV
;
1696 else if (!(info
.flags
& UBLK_F_UNPRIVILEGED_DEV
))
1699 /* the created device is always owned by current user */
1700 ublk_store_owner_uid_gid(&info
.owner_uid
, &info
.owner_gid
);
1702 if (header
->dev_id
!= info
.dev_id
) {
1703 pr_warn("%s: dev id not match %u %u\n",
1704 __func__
, header
->dev_id
, info
.dev_id
);
1708 ublk_dump_dev_info(&info
);
1710 ret
= mutex_lock_killable(&ublk_ctl_mutex
);
1715 if (ublks_added
>= ublks_max
)
1719 ub
= kzalloc(sizeof(*ub
), GFP_KERNEL
);
1722 mutex_init(&ub
->mutex
);
1723 spin_lock_init(&ub
->mm_lock
);
1724 INIT_WORK(&ub
->quiesce_work
, ublk_quiesce_work_fn
);
1725 INIT_WORK(&ub
->stop_work
, ublk_stop_work_fn
);
1726 INIT_DELAYED_WORK(&ub
->monitor_work
, ublk_daemon_monitor_work
);
1728 ret
= ublk_alloc_dev_number(ub
, header
->dev_id
);
1732 memcpy(&ub
->dev_info
, &info
, sizeof(info
));
1734 /* update device id */
1735 ub
->dev_info
.dev_id
= ub
->ub_number
;
1738 * 64bit flags will be copied back to userspace as feature
1739 * negotiation result, so have to clear flags which driver
1740 * doesn't support yet, then userspace can get correct flags
1741 * (features) to handle.
1743 ub
->dev_info
.flags
&= UBLK_F_ALL
;
1745 if (!IS_BUILTIN(CONFIG_BLK_DEV_UBLK
))
1746 ub
->dev_info
.flags
|= UBLK_F_URING_CMD_COMP_IN_TASK
;
1748 /* We are not ready to support zero copy */
1749 ub
->dev_info
.flags
&= ~UBLK_F_SUPPORT_ZERO_COPY
;
1751 ub
->dev_info
.nr_hw_queues
= min_t(unsigned int,
1752 ub
->dev_info
.nr_hw_queues
, nr_cpu_ids
);
1753 ublk_align_max_io_size(ub
);
1755 ret
= ublk_init_queues(ub
);
1757 goto out_free_dev_number
;
1759 ret
= ublk_add_tag_set(ub
);
1761 goto out_deinit_queues
;
1764 if (copy_to_user(argp
, &ub
->dev_info
, sizeof(info
)))
1765 goto out_free_tag_set
;
1768 * Add the char dev so that ublksrv daemon can be setup.
1769 * ublk_add_chdev() will cleanup everything if it fails.
1771 ret
= ublk_add_chdev(ub
);
1775 blk_mq_free_tag_set(&ub
->tag_set
);
1777 ublk_deinit_queues(ub
);
1778 out_free_dev_number
:
1779 ublk_free_dev_number(ub
);
1781 mutex_destroy(&ub
->mutex
);
1784 mutex_unlock(&ublk_ctl_mutex
);
1788 static inline bool ublk_idr_freed(int id
)
1792 spin_lock(&ublk_idr_lock
);
1793 ptr
= idr_find(&ublk_index_idr
, id
);
1794 spin_unlock(&ublk_idr_lock
);
1799 static int ublk_ctrl_del_dev(struct ublk_device
**p_ub
)
1801 struct ublk_device
*ub
= *p_ub
;
1802 int idx
= ub
->ub_number
;
1805 ret
= mutex_lock_killable(&ublk_ctl_mutex
);
1809 if (!test_bit(UB_STATE_DELETED
, &ub
->state
)) {
1811 set_bit(UB_STATE_DELETED
, &ub
->state
);
1814 /* Mark the reference as consumed */
1816 ublk_put_device(ub
);
1817 mutex_unlock(&ublk_ctl_mutex
);
1820 * Wait until the idr is removed, then it can be reused after
1821 * DEL_DEV command is returned.
1823 * If we returns because of user interrupt, future delete command
1826 * - the device number isn't freed, this device won't or needn't
1827 * be deleted again, since UB_STATE_DELETED is set, and device
1828 * will be released after the last reference is dropped
1830 * - the device number is freed already, we will not find this
1831 * device via ublk_get_device_from_id()
1833 wait_event_interruptible(ublk_idr_wq
, ublk_idr_freed(idx
));
1838 static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd
*cmd
)
1840 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1842 pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n",
1843 __func__
, cmd
->cmd_op
, header
->dev_id
, header
->queue_id
,
1844 header
->data
[0], header
->addr
, header
->len
);
1847 static int ublk_ctrl_stop_dev(struct ublk_device
*ub
)
1850 cancel_work_sync(&ub
->stop_work
);
1851 cancel_work_sync(&ub
->quiesce_work
);
1856 static int ublk_ctrl_get_dev_info(struct ublk_device
*ub
,
1857 struct io_uring_cmd
*cmd
)
1859 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1860 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1862 if (header
->len
< sizeof(struct ublksrv_ctrl_dev_info
) || !header
->addr
)
1865 if (copy_to_user(argp
, &ub
->dev_info
, sizeof(ub
->dev_info
)))
1871 /* TYPE_DEVT is readonly, so fill it up before returning to userspace */
1872 static void ublk_ctrl_fill_params_devt(struct ublk_device
*ub
)
1874 ub
->params
.devt
.char_major
= MAJOR(ub
->cdev_dev
.devt
);
1875 ub
->params
.devt
.char_minor
= MINOR(ub
->cdev_dev
.devt
);
1878 ub
->params
.devt
.disk_major
= MAJOR(disk_devt(ub
->ub_disk
));
1879 ub
->params
.devt
.disk_minor
= MINOR(disk_devt(ub
->ub_disk
));
1881 ub
->params
.devt
.disk_major
= 0;
1882 ub
->params
.devt
.disk_minor
= 0;
1884 ub
->params
.types
|= UBLK_PARAM_TYPE_DEVT
;
1887 static int ublk_ctrl_get_params(struct ublk_device
*ub
,
1888 struct io_uring_cmd
*cmd
)
1890 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1891 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1892 struct ublk_params_header ph
;
1895 if (header
->len
<= sizeof(ph
) || !header
->addr
)
1898 if (copy_from_user(&ph
, argp
, sizeof(ph
)))
1901 if (ph
.len
> header
->len
|| !ph
.len
)
1904 if (ph
.len
> sizeof(struct ublk_params
))
1905 ph
.len
= sizeof(struct ublk_params
);
1907 mutex_lock(&ub
->mutex
);
1908 ublk_ctrl_fill_params_devt(ub
);
1909 if (copy_to_user(argp
, &ub
->params
, ph
.len
))
1913 mutex_unlock(&ub
->mutex
);
1918 static int ublk_ctrl_set_params(struct ublk_device
*ub
,
1919 struct io_uring_cmd
*cmd
)
1921 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1922 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
1923 struct ublk_params_header ph
;
1926 if (header
->len
<= sizeof(ph
) || !header
->addr
)
1929 if (copy_from_user(&ph
, argp
, sizeof(ph
)))
1932 if (ph
.len
> header
->len
|| !ph
.len
|| !ph
.types
)
1935 if (ph
.len
> sizeof(struct ublk_params
))
1936 ph
.len
= sizeof(struct ublk_params
);
1938 /* parameters can only be changed when device isn't live */
1939 mutex_lock(&ub
->mutex
);
1940 if (ub
->dev_info
.state
== UBLK_S_DEV_LIVE
) {
1942 } else if (copy_from_user(&ub
->params
, argp
, ph
.len
)) {
1945 /* clear all we don't support yet */
1946 ub
->params
.types
&= UBLK_PARAM_TYPE_ALL
;
1947 ret
= ublk_validate_params(ub
);
1949 mutex_unlock(&ub
->mutex
);
1954 static void ublk_queue_reinit(struct ublk_device
*ub
, struct ublk_queue
*ubq
)
1958 WARN_ON_ONCE(!(ubq
->ubq_daemon
&& ubq_daemon_is_dying(ubq
)));
1959 /* All old ioucmds have to be completed */
1960 WARN_ON_ONCE(ubq
->nr_io_ready
);
1961 /* old daemon is PF_EXITING, put it now */
1962 put_task_struct(ubq
->ubq_daemon
);
1963 /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */
1964 ubq
->ubq_daemon
= NULL
;
1966 for (i
= 0; i
< ubq
->q_depth
; i
++) {
1967 struct ublk_io
*io
= &ubq
->ios
[i
];
1969 /* forget everything now and be ready for new FETCH_REQ */
1976 static int ublk_ctrl_start_recovery(struct ublk_device
*ub
,
1977 struct io_uring_cmd
*cmd
)
1979 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
1983 mutex_lock(&ub
->mutex
);
1984 if (!ublk_can_use_recovery(ub
))
1987 * START_RECOVERY is only allowd after:
1989 * (1) UB_STATE_OPEN is not set, which means the dying process is exited
1990 * and related io_uring ctx is freed so file struct of /dev/ublkcX is
1993 * (2) UBLK_S_DEV_QUIESCED is set, which means the quiesce_work:
1994 * (a)has quiesced request queue
1995 * (b)has requeued every inflight rqs whose io_flags is ACTIVE
1996 * (c)has requeued/aborted every inflight rqs whose io_flags is NOT ACTIVE
1997 * (d)has completed/camceled all ioucmds owned by ther dying process
1999 if (test_bit(UB_STATE_OPEN
, &ub
->state
) ||
2000 ub
->dev_info
.state
!= UBLK_S_DEV_QUIESCED
) {
2004 pr_devel("%s: start recovery for dev id %d.\n", __func__
, header
->dev_id
);
2005 for (i
= 0; i
< ub
->dev_info
.nr_hw_queues
; i
++)
2006 ublk_queue_reinit(ub
, ublk_get_queue(ub
, i
));
2007 /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */
2009 ub
->nr_queues_ready
= 0;
2010 ub
->nr_privileged_daemon
= 0;
2011 init_completion(&ub
->completion
);
2014 mutex_unlock(&ub
->mutex
);
2018 static int ublk_ctrl_end_recovery(struct ublk_device
*ub
,
2019 struct io_uring_cmd
*cmd
)
2021 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2022 int ublksrv_pid
= (int)header
->data
[0];
2025 pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n",
2026 __func__
, ub
->dev_info
.nr_hw_queues
, header
->dev_id
);
2027 /* wait until new ubq_daemon sending all FETCH_REQ */
2028 wait_for_completion_interruptible(&ub
->completion
);
2029 pr_devel("%s: All new ubq_daemons(nr: %d) are ready, dev id %d\n",
2030 __func__
, ub
->dev_info
.nr_hw_queues
, header
->dev_id
);
2032 mutex_lock(&ub
->mutex
);
2033 if (!ublk_can_use_recovery(ub
))
2036 if (ub
->dev_info
.state
!= UBLK_S_DEV_QUIESCED
) {
2040 ub
->dev_info
.ublksrv_pid
= ublksrv_pid
;
2041 pr_devel("%s: new ublksrv_pid %d, dev id %d\n",
2042 __func__
, ublksrv_pid
, header
->dev_id
);
2043 blk_mq_unquiesce_queue(ub
->ub_disk
->queue
);
2044 pr_devel("%s: queue unquiesced, dev id %d.\n",
2045 __func__
, header
->dev_id
);
2046 blk_mq_kick_requeue_list(ub
->ub_disk
->queue
);
2047 ub
->dev_info
.state
= UBLK_S_DEV_LIVE
;
2048 schedule_delayed_work(&ub
->monitor_work
, UBLK_DAEMON_MONITOR_PERIOD
);
2051 mutex_unlock(&ub
->mutex
);
2056 * All control commands are sent via /dev/ublk-control, so we have to check
2057 * the destination device's permission
2059 static int ublk_char_dev_permission(struct ublk_device
*ub
,
2060 const char *dev_path
, int mask
)
2066 err
= kern_path(dev_path
, LOOKUP_FOLLOW
, &path
);
2070 err
= vfs_getattr(&path
, &stat
, STATX_TYPE
, AT_STATX_SYNC_AS_STAT
);
2075 if (stat
.rdev
!= ub
->cdev_dev
.devt
|| !S_ISCHR(stat
.mode
))
2078 err
= inode_permission(&nop_mnt_idmap
,
2079 d_backing_inode(path
.dentry
), mask
);
2085 static int ublk_ctrl_uring_cmd_permission(struct ublk_device
*ub
,
2086 struct io_uring_cmd
*cmd
)
2088 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2089 bool unprivileged
= ub
->dev_info
.flags
& UBLK_F_UNPRIVILEGED_DEV
;
2090 void __user
*argp
= (void __user
*)(unsigned long)header
->addr
;
2091 char *dev_path
= NULL
;
2095 if (!unprivileged
) {
2096 if (!capable(CAP_SYS_ADMIN
))
2099 * The new added command of UBLK_CMD_GET_DEV_INFO2 includes
2100 * char_dev_path in payload too, since userspace may not
2101 * know if the specified device is created as unprivileged
2104 if (cmd
->cmd_op
!= UBLK_CMD_GET_DEV_INFO2
)
2109 * User has to provide the char device path for unprivileged ublk
2111 * header->addr always points to the dev path buffer, and
2112 * header->dev_path_len records length of dev path buffer.
2114 if (!header
->dev_path_len
|| header
->dev_path_len
> PATH_MAX
)
2117 if (header
->len
< header
->dev_path_len
)
2120 dev_path
= kmalloc(header
->dev_path_len
+ 1, GFP_KERNEL
);
2125 if (copy_from_user(dev_path
, argp
, header
->dev_path_len
))
2127 dev_path
[header
->dev_path_len
] = 0;
2130 switch (cmd
->cmd_op
) {
2131 case UBLK_CMD_GET_DEV_INFO
:
2132 case UBLK_CMD_GET_DEV_INFO2
:
2133 case UBLK_CMD_GET_QUEUE_AFFINITY
:
2134 case UBLK_CMD_GET_PARAMS
:
2137 case UBLK_CMD_START_DEV
:
2138 case UBLK_CMD_STOP_DEV
:
2139 case UBLK_CMD_ADD_DEV
:
2140 case UBLK_CMD_DEL_DEV
:
2141 case UBLK_CMD_SET_PARAMS
:
2142 case UBLK_CMD_START_USER_RECOVERY
:
2143 case UBLK_CMD_END_USER_RECOVERY
:
2144 mask
= MAY_READ
| MAY_WRITE
;
2150 ret
= ublk_char_dev_permission(ub
, dev_path
, mask
);
2152 header
->len
-= header
->dev_path_len
;
2153 header
->addr
+= header
->dev_path_len
;
2155 pr_devel("%s: dev id %d cmd_op %x uid %d gid %d path %s ret %d\n",
2156 __func__
, ub
->ub_number
, cmd
->cmd_op
,
2157 ub
->dev_info
.owner_uid
, ub
->dev_info
.owner_gid
,
2164 static int ublk_ctrl_uring_cmd(struct io_uring_cmd
*cmd
,
2165 unsigned int issue_flags
)
2167 struct ublksrv_ctrl_cmd
*header
= (struct ublksrv_ctrl_cmd
*)cmd
->cmd
;
2168 struct ublk_device
*ub
= NULL
;
2171 if (issue_flags
& IO_URING_F_NONBLOCK
)
2174 ublk_ctrl_cmd_dump(cmd
);
2176 if (!(issue_flags
& IO_URING_F_SQE128
))
2179 if (cmd
->cmd_op
!= UBLK_CMD_ADD_DEV
) {
2181 ub
= ublk_get_device_from_id(header
->dev_id
);
2185 ret
= ublk_ctrl_uring_cmd_permission(ub
, cmd
);
2187 /* ADD_DEV permission check is done in command handler */
2194 switch (cmd
->cmd_op
) {
2195 case UBLK_CMD_START_DEV
:
2196 ret
= ublk_ctrl_start_dev(ub
, cmd
);
2198 case UBLK_CMD_STOP_DEV
:
2199 ret
= ublk_ctrl_stop_dev(ub
);
2201 case UBLK_CMD_GET_DEV_INFO
:
2202 case UBLK_CMD_GET_DEV_INFO2
:
2203 ret
= ublk_ctrl_get_dev_info(ub
, cmd
);
2205 case UBLK_CMD_ADD_DEV
:
2206 ret
= ublk_ctrl_add_dev(cmd
);
2208 case UBLK_CMD_DEL_DEV
:
2209 ret
= ublk_ctrl_del_dev(&ub
);
2211 case UBLK_CMD_GET_QUEUE_AFFINITY
:
2212 ret
= ublk_ctrl_get_queue_affinity(ub
, cmd
);
2214 case UBLK_CMD_GET_PARAMS
:
2215 ret
= ublk_ctrl_get_params(ub
, cmd
);
2217 case UBLK_CMD_SET_PARAMS
:
2218 ret
= ublk_ctrl_set_params(ub
, cmd
);
2220 case UBLK_CMD_START_USER_RECOVERY
:
2221 ret
= ublk_ctrl_start_recovery(ub
, cmd
);
2223 case UBLK_CMD_END_USER_RECOVERY
:
2224 ret
= ublk_ctrl_end_recovery(ub
, cmd
);
2233 ublk_put_device(ub
);
2235 io_uring_cmd_done(cmd
, ret
, 0);
2236 pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n",
2237 __func__
, ret
, cmd
->cmd_op
, header
->dev_id
, header
->queue_id
);
2238 return -EIOCBQUEUED
;
2241 static const struct file_operations ublk_ctl_fops
= {
2242 .open
= nonseekable_open
,
2243 .uring_cmd
= ublk_ctrl_uring_cmd
,
2244 .owner
= THIS_MODULE
,
2245 .llseek
= noop_llseek
,
2248 static struct miscdevice ublk_misc
= {
2249 .minor
= MISC_DYNAMIC_MINOR
,
2250 .name
= "ublk-control",
2251 .fops
= &ublk_ctl_fops
,
2254 static int __init
ublk_init(void)
2258 init_waitqueue_head(&ublk_idr_wq
);
2260 ret
= misc_register(&ublk_misc
);
2264 ret
= alloc_chrdev_region(&ublk_chr_devt
, 0, UBLK_MINORS
, "ublk-char");
2266 goto unregister_mis
;
2268 ublk_chr_class
= class_create(THIS_MODULE
, "ublk-char");
2269 if (IS_ERR(ublk_chr_class
)) {
2270 ret
= PTR_ERR(ublk_chr_class
);
2271 goto free_chrdev_region
;
2276 unregister_chrdev_region(ublk_chr_devt
, UBLK_MINORS
);
2278 misc_deregister(&ublk_misc
);
2282 static void __exit
ublk_exit(void)
2284 struct ublk_device
*ub
;
2287 idr_for_each_entry(&ublk_index_idr
, ub
, id
)
2290 class_destroy(ublk_chr_class
);
2291 misc_deregister(&ublk_misc
);
2293 idr_destroy(&ublk_index_idr
);
2294 unregister_chrdev_region(ublk_chr_devt
, UBLK_MINORS
);
2297 module_init(ublk_init
);
2298 module_exit(ublk_exit
);
2300 module_param(ublks_max
, int, 0444);
2301 MODULE_PARM_DESC(ublks_max
, "max number of ublk devices allowed to add(default: 64)");
2303 MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>");
2304 MODULE_LICENSE("GPL");